The licensing update has been executed.The results are available here. Please be aware that pages need to be updated to reflect the result and that some information may be obsolete. In the meantime, viewing the LU timeline might be helpful. Help with translations is of continuing appreciation.

Text published in Wikipedia and other Wikimedia Foundation projects is under copyright. However, the Wikimedia community is committed to principles of free information similar to the principles that have been articulated for software by the free software and open source movements, allowing anyone to re-use the information for any purpose. This is accomplished through licenses which grant freedoms that people would not have under traditional copyright.

The license chosen for Wikipedia is the GNU Free Documentation License (GFDL) developed and maintained by the Free Software Foundation. Underscoring the deep connection between Wikipedia and the free software community, this license was originally developed for freely licensed software documentation. However, as Wikipedia and the other projects have grown and continued to expand rapidly, it has become increasingly apparent that Wikimedia is no longer as suited to this license as it may once have been. Therefore, to make Wikipedia content easier to use and legally compatible with existing free content projects, the Wikimedia Foundation intends to submit a proposal to the Wikimedia community to make all content currently distributed by the Wikimedia Foundation under the GFDL available under the CC-BY-SA 3.0 license, where CC-BY-SA will exclude GFDL whenever third party content only licensed under the CC-BY-SA license is imported; this, as well as why the CC-BY-SA is proposed to be more fitting, is explained in detail below.

The GFDL has been recently updated in a fashion to make this re-licensing possible without direct petitioning of each copyright holder who contributed to a collaborative work (see below). The decision on whether to update the licensing terms is nevertheless intended to be democratically made through a global, community-wide vote, where a simple majority of qualified users will constitute sufficient support to make this switch. The vote has begun by early April, and will end on May 3rd.

Why is the Wikimedia Foundation interested in moving from the GNU Free Documentation License (GFDL) to the Creative Commons Attribution Share-Alike license (CC-BY-SA)?

To begin with a quote by Jimmy Wales:

"When I started Wikipedia, Creative Commons did not exist. The Free Documentation License was the first license that demonstrated well how the principles of the free software movement could be applied to other kinds of works. However, it is designed for a specific category of works: software documentation. The CC-BY-SA license is a more generic license that meets the needs of Wikipedia today, and I'm very grateful that the FSF has allowed this change to happen. Switching to CC-BY-SA will also allow content from our projects to be freely mixed with CC-BY-SA content. It's a critically necessary change for the future of Wikimedia."

The GFDL was originally formulated to address a specific set of problems, including the possibility that some companies might use non-free documentation as a way of encumbering otherwise free software. The design decisions that went into development of a documentation license don't always address the problems that come up with massive multi-user collaboration projects like Wikipedia, and they may in fact create new problems that make free content less easy to use.

This is a large part of the reason why Creative Commons has designed a specific generic copyleft license for works which are not software, the CC-BY-SA license. The Creative Commons licenses have seen rapid adoption on the web, with more than 130 million works estimated to be licensed under one of them (see Creative Commons Metrics for statistics). Unfortunately, works under CC-BY-SA and GFDL cannot directly be combined, creating an unnecessary but highly problematic compatibility barrier within the free culture movement.

The Free Software Foundation (which maintains the GFDL), Creative Commons (which maintains the CC-BY-SA license), and the Wikimedia Foundation (which operates Wikipedia among other free-culture projects) have been working together to develop a pathway to "migrate" or "re-license" Wikipedia content (and the content of similar wikis) to the CC-BY-SA license that combines the free-culture values of the GFDL with greater practical usability in the context of collaborative works.

In which way has the GFDL, which seems to me to have worked just fine, been a problem for Wikipedia or its communities of editors and users?

Community member David Gerard has provided a nice summary of the issues for us, so in the spirit of reusing useful content, we're adapting his summary:

The GFDL was written as a license for software manuals on paper with one or a few authors. It's not at all suited to wiki content with possibly hundreds of editors. Wikipedia's predecessor, Nupedia, eventually adopted it at the time because the CC-BY-SA license didn't exist yet.

The GFDL is very difficult to follow in practice, at least in contexts like massive multiuser collaborative projects like Wikipedia.

Trying to obey can be onerous. Per the letter of the license, every significant (greater than fair use) quotation from a GFDL work needs a copy of the license (three or so pages of print) attached. GFDL content is almost impossible to reuse in audio or video content for this reason.

Although easy to follow on the web (link to a local copy of the GFDL) or in a book (reproduce the three-page license), it's almost impossible to reuse in shorter pieces.

The 'how to comply' pages on various Wikipedias are more what individual editors think is a good idea, not necessarily what the letter of the license says – as has been complained of by reusers accused of violation for not following this month's interpretation.

Even cutting and pasting text between two Wikipedia articles is technically a violation unless the full author list for that piece of text is attached. This is not workable on a wiki.

CC-BY-SA is becoming the usual license for free content intended to stay free ('copyleft'). That's a whole world of text, images, movies and so on that Wikimedia stuff can't be mixed with. (A software analogy is using a copyleft license that's not GPL-compatible – it makes your work an isolated island for no particular gain.)

It is also worth pointing out that a literal interpretation of the attribution requirement of the GFDL requires complete duplication of the "history" section of the article with every derivative work (not just the author names – the entire section). For an article with thousands of revisions, this is obviously highly onerous, but even with just a smaller number of revisions, it is a significant amount of text.

What is the history of the negotiations to allow this migration to happen?

This migration path has been the subject of discussions among the FSF, Creative Commons, and the Wikimedia Foundation for several years. These have been friendly discussions, and the participants have all shared the goal of ensuring that "relicensed" or "migrated" content is strongly free, and consistent with strong "copyleft" principles. To some extent the discussions have centered on a widely acknowledged fact – that Wikipedia is one of the largest pools of free information, but because of licensing issues it can't always be easily reused, remixed, and combined with other stuff available under the somewhat different but similarly intentioned CC-BY-SA license (which is widely used elsewhere on the Net). In fact, several other Wikimedia Foundation projects also use CC-BY-SA, so one of the goals here is to bring Wikipedia licensing into greater harmony with that of other Wikimedia Foundation project content.

On December 1, 2007, the Wikimedia Foundation Board of Trustees made the important decision to officially request the implementation of a migration path to CC-BY-SA in the GFDL 1.3 license. This decision also included a commitment to "community discussion and voting" before any change would be implemented on Wikimedia Foundation websites.

I notice the date for eligibility of relicensable content is November 1, 2008 – that date has already come and gone. Why didn't you use a future date instead of one that's already passed?

The goal here was not to trigger a "rush to migration," but instead to provide a path for existing projects to consider and adopt a switch between licenses. As the Free Software Foundation indicates in its own FAQ: "if a work was originally published somewhere other than a public wiki, you can only use it under CC-BY-SA 3.0 if it was added to a wiki before November 1, 2008. We do not want to grant people this permission for any and all works released under the GFDL. We also do not want people gaming the system by adding GFDLed materials to a wiki, and then using them under CC-BY-SA afterwards. Choosing a deadline that has already passed unambiguously prevents this."

This does not affect our ability to migrate content originating in our wikis, only the ability to re-license content originating outside the Wikimedia Foundation wikis.

Isn't the FSF granting this permission and then removing it down the line – in August 2009? Isn't that arbitrary? If migrating between licenses is a good thing, why ever put an end date on the option?

It helps again to refer to the Free Software Foundation's FAQ. The goal of this negotiation has not been to make it forever easy to switch among free licenses but to address the fact that the basic license for Wikipedia (and many similar wikis) is a license that was not particularly well-suited for wiki collaboration because it was developed for a different set of purposes. As the FSF FAQ puts it: "[T]his permission is no longer available after August 1, 2009. We don't want this to become a general permission to switch between licenses: the community will be much better off if each wiki makes its own decision about which license it would rather use, and sticks with that. This deadline ensures that outcome, while still offering all wiki maintainers ample time to make their decision."

So are you basically trying to replace the GFDL on Wikipedia with CC-BY-SA?

No, we are proposing that all content currently available under GFDL will also be made available under the CC-BY-SA license, and that all future revisions must be dual licensed, with the exception of CC-BY-SA-only additions from external sources. See the main proposal for details.

It simply means that content will be available under both the GFDL and CC-BY-SA licenses simultaneously, unless some CC-BY-SA-only materials are imported and incorporated into that piece of content. In other words, reusers will be able to choose whether to reuse Wikipedia content under the GFDL license or the CC-BY-SA license (with a few exceptions). We have worked with FSF and others to try to implement dual-licensing in a way that requires relatively little administrative overhead (or editor or user overhead). The outline of this arrangement were spelled out in e-mail by Richard Stallman, who was mindful of the need to make the problems of dual-licensing manageable:

ALL contributors agree to the following:

Wikipedia can release their newly written text under both GFDL and CC-BY-SA in parallel. However, if they imported any external material that's available under CC-BY-SA and not under GFDL, Wikipedia is bound by that.

All old revisions are released under GFDL and CC-BY-SA.

All new revisions are released with this license statement:

This page is released under CC-BY-SA. Depending on its editing history, it MAY also be available under the GFDL; see [link] for how to determine that.

Isn't dual-licensing a complicated solution to this situation?

We believe Richard has done well at outlining an appropriate implementation for dual-licensing – we believe that this dual-licensing compromise should ideally allow both dual-licensing proponents and dual-licensing opponents to support the switch. We recognize that this compromise won't fully please everyone, but hope neither the pro-dual-licensing side nor its opponents will dig their feet in. Part of the reason to keep GFDL integrated in the way we are proposing here is precisely that the GFDL has been of unquestionable value for Wikipedia over the years. We recognize that FSF is going forward in its own efforts to revise and evolve the GFDL. If you help us move forward with this compromise, we can revisit the dual-licensing situation in a year or two together with the FSF and see if it still is needed.

It will be the obligation of re-users to validate whether an article includes CC-BY-SA-only changes – dual licensing should not be a burden on editors. This is also not intended to be bidirectional, so merging in GFDL-only text will not be possible.

What about merging in GFDL-only content?

While merging GFDL-only text into WikiMedia projects will ultimately no longer be possible, we propose to continue to permit GFDL 1.2-only media uploads for the foreseeable future, to address concerns regarding strong and weak copyleft, until such concerns are fully resolved to the satisfaction of community members. (For a discussion of "strong copyleft" versus "weak copyleft," see generally the Wikipedia entry on "Copyleft".)

How will re-users determine whether or not an article is available under GFDL?

The CC-BY-SA license requires attribution, so when third party content is imported under "CC-BY-SA-only", it will have to be noted who the author is and that it was released under CC-BY-SA, as part of the normal, existing procedures through which projects make note of such histories (we recommend the article footer or the version history). Re-users will have to consult this information to determine whether CC-BY-SA-only content has been imported. Our licensing guidelines will make that clear.

Is the idea to allow Wikipedia to export CC-BY-SA-licensed content? Or to allow increasing importing of CC-BY-SA-licensed content?

In a word, both. This proposal aims at least to allow both importing and exporting CC-BY-SA-licensed content. Some very large projects already have adopted CC-BY-SA as a standard license. One of our goals here is to enable Wikipedia content to fuel these other projects more easily, and for them to provide content to us as well. We think lowering the barriers between projects in this way (by migrating or relicensing Wikipedia content under a more user-friendly license) will allow all these projects to become much richer.

All that sounds good, but sometimes I wonder if this is somehow a plot against the Free Software Foundation by Creative Commons folks – I seem to recall reading on mailing lists that there's some distrust between these groups.

Our experience has been that nobody's been plotting against anybody, and that all the participants have been remarkably friendly and cooperative, with their "eyes on the prize" of developing greater interoperability and compatibility among free-culture projects. It is worth emphasizing that Creative Commons has tried to recognize the strong commitment to freedom by the Wikimedia community in three ways:

by publishing a Statement of Intent regarding the CC-BY-SA license to clarify the purpose and future of the license;

by directly engaging with our community on our mailing lists regarding these issues.

Why didn't the FSF just say "OK, the next GFDL is the same as CC-BY-SA?"

"Because, despite Wikimedia sites being by far the largest corpus of GFDL content, the FSF needed to keep important details of how the license works the same for its original audience: authors of software manuals. Plus, many software manuals use features of the GFDL that are not in CC-BY-SA, such as provisions for cover texts and 'invariant sections.'" — David Gerard

If the GFDL is so difficult for editors and users, why was it adopted for Wikipedia in the first place?

At the time Wikipedia began, there had already been some experimentation with other attempts at free licenses (at Nupedia and elsewhere), but none of them had the successful track record of the GFDL. At the same time, the Creative Commons free licenses had not been developed (or at least not in their current form). So GFDL at the time was the best option available. Now that GFDL has evolved, and CC-BY-SA is available, we have a better option available, and one that will provide more compatibility among free-culture projects.

Our experience has been that relatively few editors and users are engaged enough with the licensing issues we're discussing here to be affected in any significant way by the update (not that we are attempting to stereotype the "average editor" when we say that). However, we believe the difference will be significant for other communities and individuals developing content.

Isn't this new migration clause "surprising" and therefore legally invalid?

We believe that the migration clause is consistent with the language used in the GFDL 1.2: "The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns." The use of the GFDL by Wikipedia has given rise to "new problems or concerns", which were addressed by giving a migration path to a license "similar in spirit" which is, however, simpler to use in the context in which we are currently using the GFDL. While the specific wording of CC-BY-SA is different from that of the GFDL, the freedoms it guarantees and preserves are identical, and thanks to the Statement of Intent by Creative Commons, are guaranteed to be protected in the long term. The Free Software Foundation is a responsible custodian of its licenses and has made this change to the FDL in full awareness of its implications.

Are such unilateral changes to a license legal in all jurisdictions where people may wish to re-use our content?

We believe that licensing updates that do not fundamentally alter the spirit of the license and that are permitted through the license itself are legally valid in all jurisdictions.

Which licensing is suggested for other wiki projects (presently under GFDL, too) for the best interchange with WMF projects?

There are two paths here. One path would be for a wiki project currently under GFDL to take advantage of the new GFDL version (within the specified time period) and dual-license its content precisely as Wikipedia is currently proposing to dual-license its own content. Another path would be simply to license (or relicense) one's wiki under CC-BY-SA 3.x or later.

And for the transition period? ("Transition period" is the time from publishing GFDL 1.3 up to adoption of dual licensing policy at Wikimedia projects.)

To be prepared for any outcome of the community consultation, dual-licensing is the safest solution.

It will affect both text and images, except for images which are licensed under "GFDL 1.2 only". Those will not be dual-licensed.

If the migration occurs, will it change what image licenses are allowed to be used on WMF projects?

Not immediately. It is possible that, at some future point, GFDL 1.2 media may be disallowed. However, this will only happen if CC-BY-SA is modified to make it more explicitly a "strong copyleft" license for embedded media, requiring the surrounding content to be licensed under CC-BY-SA. Currently both licenses are somewhat ambiguous in this regard.

It is also worth pointing out that a literal interpretation of the attribution requirement of the GFDL requires complete duplication of the "history" section of the article with every derivative work (not just the author names – the entire section). For an article with thousands of revisions, this is obviously highly onerous, but even with just a smaller number of revisions, it is a significant amount of text.

How will this "onerous" requirement be avoided using CC-BY-SA?

The primary attribution mechanism (visible credit) recognized in GFDL documents is attribution through the title page, limited to principal authors. Our own terms of use (e.g. English Wikipedia example notice) have generally allowed people to give credit by referencing the article or history page, but those terms did not meet the requirements of the GFDL to the letter. The History page reachable from a Wikipedia article could be interpreted as not being a "section" or a "named subunit" as required by the license (it can also be on a different server than the page's one); similarly, there's not a Title page.

Given our own existing site terms as well as the actual ways in which credit is given in Wikipedia to a contributor, we believe a consistent approach to attribution in Wikipedia is to state a requirement to attribute articles by linking to them. CC-BY-SA allows for this attribution model, as it permits the author to require attribution-by-name or attribution-by-URL. That this approach is consistent with the language and intent of CC-BY-SA has been validated by Creative Commons General Counsel. An exploratory survey conducted in the English and German Wikipedia also suggests that this model is the preferred attribution model by the Wikipedia community and represents the best reconciliation of our desire to credit authors, and our mission to facilitate the free exchange of knowledge.

The "History" section of GFDL documents exists for purposes of change tracking. CC-BY-SA does not include significant change tracking requirements, except for giving a reasonable indicator that a document has been modified from its original version.

To prevent manipulation of the vote and to protect the secrecy of ballots, the vote is being administered by an independent third party, Software in the Public Interest, Inc., a non-profit organization. SPI has also previously administered an election to the Board of Trustees of the Wikimedia Foundation. SPI runs an installation of the MediaWiki software with the SecurePoll extension.

The vote results will be tallied by the licensing committee, an independent group of Wikimedia volunteers. Per the Access to nonpublic data policy, information about IP addresses is limited to users who have disclosed their age and identity to the Wikimedia Foundation, and who are above the age of majority in their jurisdiction.

What information is sent to SPI and how does the session transfer work?

Wikimedia sends the following information about voters to SPI:

User name

Blocked status

Edit count

Group membership

Language preference

Of these, only the language preference is private data. Wikimedia also sends an authentication token which is specific to SecurePoll and is not useful for any other purpose. Forensic information such as IP address is gathered by the SPI server directly from the user.

Technically, session transfer works as follows:

Wikimedia gives the user a secret token

The user sends the token to SPI by clicking the jump button

SPI sends the token back to Wikimedia, to auth-api.php via HTTPS, for verification

Wikimedia verifies the token and provides user data

SPI checks the voter qualifications using this information, creates a voter ID, and sets a local session cookie.